Automatic telephone signaling system.



M. suwA.

AUTOMATIC TELEPHONE SIGNALING SYSTEM.

APPLICATION FILED 0on1. 1913.

1,142,857, Patenfed June 15,1915. 7

2 SHEETS-SHEET 1..

IHVEHTOR WITNESSES M PETERS CO4. FHOTO-LITHQ. WASHINGTON. D. C.

M. SUWA.

AUTOMATIC TELEPHONE SIGNALING SYSTEM.

APPLICATION FILED ocT. 1. 191a.

Patented June 15, 1915.

2 SHEETS-SHEET 2- INVENTDR THE NORRIS PETERS CO.. PHOTO-L'THQ. WASHINGTON. D. C.

pnirsn snares PATENT @FEECE.

MIOI-IISUYE SUWA, OF TOKYO, JAPAN.

AUTOMATIC TELEPHONE SIGNALING SYSTEM.

Specification of Letters Patent.

Patented June 15, 1915.

Application filed October 7, 1913. Serial No. 793,972.

vparatus Called Automatic Telephone Signaling System, of which the following is a specification. I a

This invention relates to a telephone system in which a telephone when not in use is kept inoperative by the potential balance of batteries, and is characterized by the fact that it permits, when applied to'a telephone of a local battery system, of maintaining the potential balance of the batteries, when not in service.

It consists of a special arrangement of electric lines by which, while the telephone is in use, thelocal batteries are cut olf from the signaling circuits.

Referring to the drawings, which form part of this specification, Figure 1 shows the lines connecting two telephones when the telephones are not in use, and Fig. 2 the same when in use. Fig.3 shows, by way of example, the application of this system pro- 'vided with a switchboard for several sets of telephones. I p

The signaling circuits 2 and 2 of the two telephones are connected at the same time by the outer lines 1 and 1, when the telephones are not in use, and batteries 3 and 3 of equal potential are applied to both telephones, in order to work in opposition or neutralize each other in each of the signaling circuits 2 and 2, when the signaling lines in common are closed. The drawing shows a simple example of the batteries 3 and 3, when such are used also for transmitting purposes. Thus in the two telephones A and B, the one end of the signaling lines 2 and 2 connected with the bell 4 or a signal relay has a contact point 5, which is in contact with the hook 6 connected to the outer line 1, while the other end is connected through the battery 3 to one end of the transmitter circuit 8 of the transmitter 7, and at the same time to the other outer line 1 as well as to one end of the receiver circuit 10 leading to the receiver 9.

When, as shown in Fig. 1, the telephones are not in use, and the receiver 9 is hung on the hook 6, the contact point 5 and the hook 6 are in contact with each other, and a signaling circuit common to both telephones is closed by the signaling circuits 2 and 2, a part of the transmitter circuits 8 and 8, and

the outer lines 1 and 1. As the batteries 3 and 3 of the two telephones are so placed as to work in opposition through the circuit, it is kept entirely inactive, no current flowing on account of potential balance. When the telephones are about to be used, and the receiver 9 of one of them such as A,'Fig. 2, is removed, the contact point 5, as shown in Fig. 2, is off the hook 6, the signaling circuit 2 of that telephone being disconnected,

and at the same time the transmitter circuit '8 and the receiver circuit 10 are closed; the telephone on the other side is, however, still in the position in Fig. 1, B, and thus the telephone B is able to connect for itself the signaling lines by the signaling circuit 2, the outer lines 1 and 1, and the receiver circuit 10 of the telephone A, and thus it will break up the potential balance between the two batteries and render the bell 4 operative, by

the battery 3, to signal to the telephone B.

Ifthe resistances of the outer lines 1 and 1 is too high, another battery 11, as shown in Fig. 1, may be added to the signaling circuits 2 and 2, makingup moderately the want of strength of the current.

The above is an example of the application to a wall-set telephone, the same system may, however, be applied to various forms of telephone.

The above explanation refers to a simple pair of telephones, but when a switchboard is used the invention may be applied to several sets of telephones while fulfilling the conditions to keep them inoperative by the potential balance of batteries, which is the chief characteristic of the present invention.

Fig. 3 is a case of such applicatiom'where A, B, etc., represent the subscribers'telephones, 12 the signaling eircuit of a switchboard to be closed in common with that of each telephone by the outer lines 1 and 1 when the telephone is not in use; 13 a battery placed in the signaling line 12 so as to have potential balance against a battery 3; 14 a relay placed in the signaling line; 15 a line-lamp circuit; 16 a calling-lamp; 17 a battery placed in the circuit 15 18 a clearing circuit: 19 a relay; 20 a clearing drop; 21 a cut-off relay to cause the clearing circuit to open at the same time with the working of the clearing drop; 22 a plug; and 23 a jack.

Now when a subscribers telephone is not in use (Fig. 3, the right sidel, the signaling circuit 2, the outer lines 1 and 1, and the sig naling circuit 12 of the switchboard closing the common signaling line will keep, by the potential balance of the batteries 3 and 13, the telephone inoperative; and when the receiver of the telephone A is off the hook (Fig. 3, the left side) as, by diverting the circuit in it, the battery 3 is excluded from the signaling line and the equilbrium is broken, the current of the battery 13 of the switch-board acting on the relay 14 through the signaling line 12 closes the linelamp circuit, and consequently the current of the battery 17 flows to the calling-lamp, which will glow and indicate a call. When the operator inserts the plug 22 in the ack 23 connected to the telephone A, the telephone line of the telephone A is connected to the operators telephone C. In order to ring up the wanted subscriber the operator will insert the plug 22 in the jack connected to the latters telephone, say the telephone B. Then, as this telephone is thrown out of the signaling circuit 12, the equilibrium is broken, and it makes the signal by its own battery 3. When in response to it the called subscriber removes the receiver, the line of the telephones A and B is closed, and conversation may be carried on between the subscribers. At the close of conversation, when either or both of them hang up their receivers, the current of the battery 3 of one or both of the telephones flowing through the clearing circuit 18 acts on the relay 19 and closes the line of the clearing drop, and causes the clearing drop 20 to be operated by the battery 17, and at the same moment the clearing circuit is disconnected by the cut-off relay 21. The operator will then, by drawing out the plug, restore the signaling line and bring both telephones A and B into inoperative state again.

In summing up the foregoing description, the advantages of this invention are that both positive and negative poles of two batteries in the closed signal circuits are placed in series in opposition to each other, so as to keep the telephones inoperative, by employing potential balance. Thus the leakage of electricity caused While telephones are not in use, may be avoided, and the insulation of lines is perfect even without special attention. This enables Wires to be easily fixed, and it is a most useful feature of this invention that double wire automatic signaling systems can be executed by means of batteries alone under the said terms. It will now be clear that the fixing of telephones is much easier. Ordinary telephones working an automatic signaling by means of two wires, by the common battery system, require complicated equipment, and costs not a small amount of expenditure, and it is, moreover, necessary in such construction that part of a line in the apparatus shall be cut off while the telephonesare not engaged, so that the consumption of the batterles is far from being economical. On consldering these unavoldable inconveniences ofprdinary apparatus, the present in- 1 vention is observed to be not only simple and cheap in fixing, but economical on the point of durability of batteries.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

A telephone system comprising an electrical circuit wherein the batteries of the telephones are included in independent transmitter circuits, each connected to the main line through a transformer when the receivers are removed, but included in the main line circuit and rendered inoperative by the potential balance of the batteries when the receivers are on their hooks.

In witness whereof I have hereunto set my hand in the presence of two Witnesses.

MICHISUYE SUWA. Witnesses:

DEN K -no, UHEI FUJII.

Gopies of this patent may be obtained for five cents each, by addressing the qommissioner of Eatents- Washington, D. G. 

